Rolls-Royce (www.rolls-royce.com) has announced that it has set a new record for the world’s most powerful aerospace gearbox, just months after testing began.

Speaking at the International Society for Air Breathing Engines (ISABE) conference in Manchester, Paul Stein — chief technology officer at Rolls-Royce — confirmed that the Power Gearbox had successfully reached 70,000hp while on test at Rolls-Royce’s facility in Dahlewitz, Germany.

This gearbox will play a central role in the company’s next generation UltraFan engine, delivering improved efficiency over a wide range of thrusts.

Testing of the first demonstrator gearbox began in May, using a specially designed rig; and having proven that the Power Gearbox can accommodate a power equivalent to about 400 family cars, testing will now focus on lower-power functions such as endurance and reliability.

Rolls-Royce’s Power Gearbox is designed to run all the way up to 100,000hp, and future demonstrators are expected to achieve these levels.

The Power Gearbox has a planetary design, with each ‘planet’ capable of holding the force of a Trent XWB engine at full throttle.

It is designed to allow the shafts at the core of the engine to run at very high speeds while the fan at the front of the engine runs at a lower speed.

The associated improvement in efficiency and reduction in weight will allow the UltraFan engine to offer a 25% fuel efficiency improvement over the first generation of Rolls-Royce Trent engines.

Mr Stein said: “Setting this record is a great achievement for the team, and I’m proud we’ve managed to get there so quickly.

"Our Power Gearbox technology is central to the success of the next generation of Rolls-Royce jet engines, and I’m pleased to see us pushing engineering boundaries back with this work.”

As well as high-power testing, the Power Gearbox is also undergoing ‘attitude rig testing’, which simulates the effect of the gearbox being on the wing of an aircraft in flight, through phases such as take-off, climb, banking and descent.

Rolls-Royce is working in partnership with Liebherr Aerospace (via an Aerospace Transmission Technologies joint venture) to develop manufacturing capability and capacity for the new Power Gearbox.

The UltraFan engine, available from 2025, will feature: maximum fuel burn efficiency and low emissions through a new engine core architecture; reduced weight through the use of composite carbon titanium fan blades and a composite casing; and increased efficiency through the use of ceramic matrix composites, which are heat-resistant and require less cooling air.